The Afrotropical lutefish family Citharinidae (Citharinoidei, Characiformes) comprises three genera with eight species in total. Although Citharinidae have been studied in terms of taxonomy and systematics, no cytogenetic information was available for any representative of the family. Furthermore, only one species out of 116 in Citharinoidei (Distichodus affinis Günther, 1873) has been studied cytogenetically. Here, we report the karyotypes of Citharinus citharus (Geoffroy St. Hilaire, 1809) from West Africa and Citharinus latus Müller et Troschel, 1844 from Northeast Africa. The former has the diploid chromosome number 2n = 40 and the fundamental number FN = 80, while the latter has 2n = 44 and FN = 88. Hence, these karyotypes consist exclusively of bi-armed chromosomes. Such karyotypes were previously found in D. affinis and in many lineages of Neotropical species of another suborder of Characiformes, Characoidei. In contrast, the karyotypes dominated by uni-armed elements are typical for a number of phylogenetically basal lineages of Afrotropical and Neotropical Characoidei. We discuss the importance of our data on Citharinidae for the understanding of the karyotype evolution within the order Characiformes.

中文翻译：

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根据 Characiformes 的核型进化，关于 Afrotropical lutefishes (Cithharinidae) 的第一个细胞遗传学数据

 非洲热带琵琶鱼科 Citharinidae (Citharinoidei, Characiformes) 共有三个属八个种。尽管已在分类学和系统学方面研究了 Citharinidae，但没有任何该科代表的细胞遗传学信息可用。此外，在 Cithharinoidei (Distichodus affinis Günther, 1873) 的 116 个物种中，只有一个物种经过细胞遗传学研究。在这里，我们报告了来自西非的 Citharinus citharus (Geoffroy St. Hilaire, 1809) 和来自东北非的 Citharinus latus Müller et Troschel, 1844 的核型。前者具有二倍体染色体数 2n = 40 和基本数 FN = 80，而后者具有 2n = 44 和 FN = 88。因此，这些核型仅由双臂染色体组成。这种核型以前在 D. affinis 和 Characiformes，Characoidei 的另一个亚目的新热带物种的许多谱系。相比之下，由单臂元件主导的核型对于 Afrotropical 和 Neotropical Characoidei 的许多系统发育基础谱系是典型的。我们讨论了我们关于 Citharinidae 的数据对于理解 Characiformes 目内核型进化的重要性。